[dirtyroboto]

Well Felix.
It is hard to give any solid advice or leads to employers as you really did not mention your skillset other then database management and your degree field of International Management Science.

There are many sites listing job vacancies for Japan and it should be noted that the requirments are not always as stated. You should also understand that the resume format for Japan is not like the west. I could mail you a sample resume format in Excel so you can understand the basic structure.

When a Japanese company advertises a position, they really go for the max in terms of native applicants. I have found this to be quite different from the truth, as most of the advertisment is done by a recruitment company.
When you make contact with the company in question there is often much less of a demand on the requirments.

Database Management is always required here in Japan. If you know your stuff and can format it into a nice resume, then you might just get what you want.
PS. It really, really, really helps if you are showing an active interest in learning Japanese. This can actually open many doors if used the right way.

Marcus.